CVE-2022-49688 afs: Fix dynamic root getattr
A null pointer dereference in the Linux kernel AFS filesystem allows local attackers to cause a system crash by stat-ing a dynamic root directory.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-49688?
CVE-2022-49688 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
afs: Fix dynamic root getattr
The recent patch to make afs_getattr consult the server didn't account for the pseudo-inodes employed by the dynamic root-type afs superblock not having a volume or a server to access, and thus an oops occurs if such a directory is stat'd.
Fix this by checking to see if the vnode->volume pointer actually points anywhere before following it in afs_getattr().
This can be tested by stat'ing a directory in /afs. It may be sufficient just to do "ls /afs" and the oops looks something like:
BUG: kernel NULL pointer dereference, address: 0000000000000020 ... RIP: 0010:afs_getattr+0x8b/0x14b ... Call Trace: <TASK> vfs_statx+0x79/0xf5 vfs_fstatat+0x49/0x62
Weakness: CWE-476
Which versions are affected by CVE-2022-49688?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49688?
Apply the vendor's patch.
Is CVE-2022-49688 being exploited?
There is no known exploitation of CVE-2022-49688 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49688, GHSA-gq92-c2vh-pqwx, UBUNTU-CVE-2022-49688.